(1) Field of the Invention
This invention relates to additive combinations useful in oils of lubricating viscosity and normally liquid fuels. More particularly, it relates to additive combinations of amino phenols with certain detergent/dispersants and to oils and fuels containing same which are especially useful in two-cycle engines.
(2) Prior Art
The book "Lubricant Additives" by M. W. Ranney, published by Noyes Data Corporation of Parkridge, N.J. (1973), discloses a number of metal salts of various sulfonic and carboxylic acids and of phenols which are useful as detergent/dispersants in lubricating oil products. The book also entitled "Lubricant Additives" by C. V. Smallheer and R. K. Smith, published by the Lezius-Hiles Co. of Cleveland, Ohio (1967), similarly discloses a number of detergent/dispersants including sulfonates, phenates and carboxylates as well as alkyl and alkenyl succinimides and other high molecular weight amides and polyamides which are useful as dispersants. Other literature, particularly patents, which also disclose similar subject matter will be noted at appropriate points in the following specification.
(3) General Background
It is well known that additives are commonly added to engine lubricant and fuel compositions to prevent deposit formation on engine and fuel system surfaces with which the lubricant or fuel may come in contact. Such deposits interfere with proper circulation of lubricants in the engine. They can also act as abrasives to increase wear of engine parts; in extreme cases, such deposits may even hinder movement of engine parts. Deposits from fuels can interfere with proper carburetor operation, increase spark plug fouling, and the like.
Among the engines which utilize such lubricants and fuels are two-cycle (two-stroke), spark-ignited internal combustion engines including rotary engines such as the Wankel-type engine. Use of these types of engines has steadily increased over the past several decades and they are presently found in power lawn mowers and other power operated garden equipment, power chain saws, pumps, electrical generators, marine out-board engines, snow-mobiles, motorcycles, other light-weight wheeled vehicles and the like.
The increasing use of two-cycle engines, coupled with the increasing severity of the conditions under which they have been operated and the need to maximize usuage of petroleum-derived materials in the face of increasing shortages, has led to an increasing demand for oils and fuels which adequately lubricate such engines (it is a common practice to add the oils used to lubricate such engines to the fuel).
Among the problems associated with the lubrication of two-cycle engines are piston ring sticking, rusting, lubrication failure of connecting rod and main bearings, and deposit formation as noted above. The formation of varnish is a particularly vexatious problem since the build-up of varnish on piston and cylinder walls can cause loss of compression through seal failing. This is particularly damaging in two-cycle engines since they depend on suction to draw the new fuel charge into the exhausted cylinder.
The unique problems and techniques associated with the lubrication of two-cycle engines has led to a recognition in the art of two-cycle engine lubricants (and fuels containing same) as distinct types of lubricants and fuels. Similarly, additive concentrates for treating such fuels and lubricants have also been recognized to be a distinct field in the art. See, for example, U.S. Pat. Nos. 3,085,975; 3,004,837; and 3,753,905.
The inventions described herein include novel additive combinations for lubricating oils and normally liquid fuels, in general, and particularly for oils and fuels used in two-cycle engines.
(4) Objects
Therefore, it is an object of this invention to provide novel additive combinations.
It is a further object of this invention to provide novel lubricants, fuels and additive concentrates containing the novel additive combinations.
It is a particular object of this invention to provide novel additive combinations and lubricants and fuels containing the same for use in two-cycle, spark-ignited engines as well as novel means for operating such engines.
Other objects will be apparent to those skilled in the art upon review of the present specification.